Intracoronary radiotherapy for restenosis.
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Biomedical subjects
Publications and source records attributed to M T Metzdorff.
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BACKGROUND: Although the platelet antiaggregant abciximab is frequently used with percutaneous coronary interventions, results of emergency coronary artery bypass graft operations in patients recently treated with abciximab are poorly characterized. METHODS: During a 29-month period, 12 patients required emergency coronary artery bypass grafting within 12 hours (mean, 1.9 hours) of abciximab therapy. Our full standard heparin dose regimen was used (mean heparin dose, 53,000 U per patient). Each patient received a single platelet transfusion dose after protamine administration, and further blood products were transfused as necessary. Clinical outcome and transfusion requirements were compared with predicted results based on risk-adjusted historical patients. RESULTS: No patients died and none were returned to the operating room for coagulopathy-related bleeding. Per patient transfusion requirements were as follows: red blood cells, 3.6 units; apheresis platelets, 1.4 units; and fresh frozen plasma, 1.5 units. As compared with predicted values, there was no excessive incidence of mortality, stroke, or red blood cell transfusion requirements. CONCLUSIONS: Emergency coronary artery bypass graft operations using full-dose heparin can be performed successfully in acutely ischemic abciximab-treated patients. Prophylactic transfusion of platelets after protamine administration appears to be useful.
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A patient scheduled for coronary revascularization was discovered to have elevated partial thromboplastin and activated clotting times. Preoperative testing revealed a lupus anticoagulant, probably secondary to long-term procainamide therapy. The resultant inability to use conventional anticoagulation monitoring for cardiopulmonary bypass was solved by direct measurement of heparin concentration. Operation and recovery were uneventful, and the patient was treated with long-term warfarin anticoagulation for this hypercoagulable state.
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Mitral valve repair for mitral regurgitation has been reported to have more favorable early and late results than mitral valve replacement. From July 1985 through July 1990, 63 patients have undergone valve repair at Good Samaritan Hospital. Twenty-two men and 41 women whose ages ranged from 34 to 81 years (mean 67.9 years) were treated. Twenty-eight patients were in New York Heart Association functional class III or IV. Twelve (19%) had undergone prior cardiac surgery. Isolated valve repair was performed in 18 patients. Valve repair was combined with coronary artery bypass grafting, other valve procedures, or aneurysm resection in the remainder (71%). Two patients (3%) died while in the hospital, and four deaths (one valve-related) occurred after discharge. Leaflet resection for ruptured chordae was done in 24 patients (38%), chordal shortening in 5 patients (8%), and leaflet transposition in 2 patients. Rigid ring annuloplasty (Carpentier) was performed in 62 patients. Eight patients required mitral valve replacement at the same operation because of unsatisfactory valve repair. Results of valve repair evaluated by echocardiography at discharge show that 48 patients (88%) are free of significant regurgitation. Follow-up to date reveals that all surviving patients who underwent valve repair have clinically improved and are stable. Four of five patients with moderate mitral regurgitation are currently asymptomatic. There have been two valve-related late failures requiring reoperation. Based on this early experience, we conclude that valve repair compared with mitral valve replacement has a low operative mortality with good early results. Continued efforts to preserve native mitral valve function in the presence of mitral regurgitation appear justified.
A consecutive series of 7104 patients undergoing isolated coronary artery bypass grafting during an 18-year period (1971 to 1988) included 469 patients older than 75 years. Results were analyzed to determine comparative risk factors for morbidity, early and late survival, and functional outcome. Patients younger than 75 years (group I) and patients older than 75 years (group II) were identical for ejection fraction and standard hemodynamic indices. Mean number of grafts and crossclamp time were greater for group II patients (p less than 0.01). Mean age of group I was 58.6 years and group II, 77.6 years (p less than 0.01). Women composed 19.7% (1308/6635) of group I and 36.2% (170/469) of group II patients (p less than 0.05). Mammary grafts were placed in 57.7% (3830/6635) of group I and 41.6% (195/469) of group II patients (p less than 0.05). Overall perioperative mortality rate was 2.1% for group I and 6.8% for group II (p less than 0.05). Perioperative myocardial infarction rate was similar for the two groups. Ventricular and supraventricular arrhythmias, renal insufficiency, neurologic complications, prolonged ventilatory support, increased hospital cost, and prolonged hospitalization were significantly more prevalent (all p less than 0.05) in patients older than 75 years. Five and 10 years postoperatively, there were no significant differences between groups I and II with regard to event-free status including angina, myocardial infarction, and reoperation. The 5-year survival rate was 92% for group I and 80% for group II (p less than 0.05), similar to that of age-matched control subjects. The significantly increased potential for complications and expense of coronary bypass in patients over 75 years of age mandates judicious patient selection and preoperative counseling. Despite a significantly increased early mortality and an anticipated decreased long-term survival paralleling normal life table survival curves, good intermediate functional improvement can be realized in patients older than 75 years, comparable with that expected in a much younger age group.
To illustrate the potential role of transcatheter bronchial artery embolization (TBAE) in the multimodality management of massive hemoptysis, we describe a case in which TBAE was successfully employed as the definitive therapy. In recent years, the technique of TBAE has joined the armamentarium of managing methods for massive hemoptysis. While massive hemoptysis has traditionally been defined in terms of the volume of blood produced within a period of time, with a rate of 600 ml in 24 hours the most commonly used definition, a more functional definition has been proposed: bleeding into the tracheobronchial tree at a rate that poses a threat to life. It is the life-threatening nature of this symptom that often results in the early involvement of thoracic surgeons in the care of these patients.
During an 18-year period a consecutive series of 6591 patients underwent primary coronary bypass grafting and 508 patients underwent reoperative bypass. The mean patient age for the reoperative group was identical to that of the primary group, 59.8 years, but the mean age at initial operation for the reoperative group was 55.2 years. Mammary grafts were done at initial operation in 59% of patients who have had one operation versus only 46% of patients who subsequently required reoperation (p less than 0.001). The overall operative mortality rate was 2.0% (134/6591) for primary coronary bypass versus 6.9% (35/508) for reoperations (p less than 0.001). Patients with a reoperative interval of 1 to 10 years had a 6.0% (18/312) mortality rate, compared with 17.6% (13/74) for those in whom the interval between operations was greater than 10 years (p less than 0.01). Ventricular arrhythmias, excessive bleeding, prolonged ventilatory support, intraaortic balloon pump insertion (all p less than 0.05), and perioperative myocardial infarction (p less than 0.001) were all more prevalent after reoperations. Including perioperative mortality, the actuarial survival rate at 5 years was 80% for reoperations versus 90% for primary operations. The corresponding figures at 10 years were 65% and 75%. The probability of undergoing reoperation within 5 and 10 years was 0.034 +/- 0.003 and 0.055 +/- 0.005, respectively. Ten years postoperatively, 36% of patients having the initial operation had recurrent angina whereas 58% of the reoperative group had significant recurrent angina. Ten years after reoperation, 30% of operative survivors were free of heart-related morbidity and mortality compared with 50% of patients having a primary operation. Univariate analysis of factors increasing the probability of reoperation include the absence of a mammary graft and younger age at operation. Patients undergoing a second bypass operation represent a substantially higher risk subgroup than patients undergoing initial operation in terms of perioperative morbidity, mortality, decreased long-term survival, and decreased relief of recurrent cardiac morbidity.
Experience over two decades in the surgical management of pulmonary atresia with intact ventricular septum demonstrates that eventual right ventricular (RV) reconstruction is possible in the majority of patients surviving valvotomy in infancy. Ten of 17 operative survivors of early valvotomy have eventually received a patch graft to the RV outflow tract, with no reoperative deaths (mean follow-up, 7.4 years). RV systolic pressures, suprasystemic prior to reoperation, are near normal after outflow patch reconstruction. Serial cineangiograms show evidence of RV growth by measurement of tricuspid annulus diameter (TAD), and demonstrate a rate of growth [d(TAD)/d(body length)] greater than a normal rate derived from autopsy data. The mean TAD growth rate is significantly greater than that of patients with less favorable ventricle types treated with a systemic-pulmonary shunt alone. Measurement of TAD is a useful method for following RV growth, and may aid in selecting patients for RV reconstruction.
Despite wide acceptance of use of sutureless intraluminal prosthetic grafts in surgical management of acute and chronic aortic dissection, their use in traumatic aortic rupture appears not to have been specifically addressed. This report describes the use of intraluminal prostheses in two cases of aortic disruption due to blunt trauma. Aortic cross-clamp times were 21 and 28 minutes, respectively. Both patients have recovered without sequelae from their aortic injuries. Although not all traumatic aortic disruptions are suitable for repair with intraluminal prostheses, the ease and safety with which this device may be employed recommends consideration of their use in appropriate cases of traumatic rupture of the aorta.
The effect of initial postischemic reperfusion temperature on myocardial preservation was studied in the isolated working rat heart model. After baseline measurement of aortic flow rate, coronary flow rate, and heart rate, 40 hearts were subjected to 60 minutes of ischemic arrest at 15 degrees C induced with a single dose of cold potassium cardioplegic solution. Hearts were then revived with a 10 minute period of nonworking reperfusion at 28 degrees, 31 degrees, 34 degrees, or 37 degrees C (10 hearts each), followed by 5 minutes of nonworking reperfusion at normothermia, followed by 30 minutes of working perfusion. Repeat measurements of function were obtained and postischemic release of creatine kinase into coronary effluent was determined. Recovery of aortic flow was significantly reduced at lower initial reperfusion temperatures (75% at 28 degrees C versus 88% at 37 degrees C) and the effect was approximately linear throughout the range studied (p less than 0.05). Release of creatine kinase into coronary effluent was greater at lower initial reperfusion temperatures (421 ImU/min/gm wet weight at 28 degrees C versus 115 ImU/min/gm wet weight at 37 degrees C), also in a linear manner (p less than 0.05). In this model, initial postischemic hypothermic reperfusion is deleterious to cellular integrity and functional recovery of the preserved myocardium. Studies in higher animals and humans are warranted to further evaluate the effect of initial reperfusion temperature on myocardial preservation.
Despite the popularity of subclavian flap aortoplasty for repair of aortic coarctation, reported experience and follow-up in neonates is surprisingly limited. This paucity of reports prompted this review of age-related late recurrence rates. Of 83 patients having subclavian flap aortoplasty from 1976 to 1983, 60 were less than 8 weeks of age at operation (mean 2.6 weeks). Operative and late mortality were 18% and 14%, respectively. After a mean follow-up of 26 months, 10 patients have experienced recurrent coarctation (a mean of 10 months elapsed between operations). For 23 patients older than 8 weeks of age at operation (mean 20 months), operative and late mortality were 13% and 10%, mean follow-up is 16 months, and no patient has yet experienced recurrence. Thus, 75% of infants less than 8 weeks of age at operation are free of recoarctation at 2 years, and 100% of older children are free of recoarctation at 2 years (p = 0.06). Review of the literature corroborates our findings. The difference in recurrence rates may be due to age-dependent involution of residual coarctation tissue unavoidably left in place during subclavian flap aortoplasty. We conclude that subclavian flap aortoplasty is effective for correction of coarctation in infants, but patients less than 8 weeks old have a significant risk of early recurrence. Based on this review and our recently reviewed experience with end-to-end anastomosis, our preference is to use the latter in this age group when technically feasible.
During the past 20 years, a consistent policy in applying early valvotomy has resulted in a unique opportunity to appraise the long-term results of this approach in pulmonary atresia with intact ventricular septum. Since 1964, 27 of 35 patients with pulmonary atresia with intact ventricular septum had type 1 or 2 right ventricle, 25 of these had early valvotomy, seven with and 18 without concomitant shunt. The remaining two patients with type 2 right ventricle and the eight patients with type 3 right ventricle received a shunt alone. Overall operative mortality was 34%; for those patients weighing more than 3 kg and those operated upon since 1977, it was 18% and 16%, respectively. There were 17 survivors of early valvotomy: 11 had valvotomy alone and six had valvotomy with shunt; 12 had type 1 right ventricle and five had type 2 right ventricle. Survival rates (+/- standard error) for these 17 patients were 85% +/- 10% and 68% +/- 17% at 5 and 10 years, respectively. The probability of reoperation was 100% by 6 years of age; outflow patch reconstruction was employed in all patients in whom reoperation has been performed. Aggressive follow-up and early recatheterization were essential features of management. Delayed reconstruction after shunt alone was unsuccessful in three patients. Primary valvotomy without shunt is the operation of choice for patients with pulmonary atresia with intact ventricular septum and type 1 right ventricle. Concomitant shunt may be required for some patients with type 1 and most with type 2 right ventricle, selected preoperatively by angiography or after valvotomy by clinical necessity. Delayed right ventricular reconstruction after shunt alone is not an acceptable approach when an outflow tract is present.
A review of 83 patients with penetrating neck wounds was performed to assess the relative merits of operation versus observation. Fifty patients (60 percent) underwent immediate surgery, 28 of whom (56 percent) had no significant neck injury. There were no deaths and only two complications (4 percent). Thirty-three patients (40 percent) were treated with initial observation, one of whom required subsequent surgery. In the latter group, there were also no deaths and two complications (6 percent). Length of hospital stay did not differ between patients with negative findings on exploration and those observed. When clinical signs as indications for surgery were present, management was more often correct than when signs were absent (82 and 52 percent, respectively), but the presence or absence of signs correctly predicted injury or lack of injury in over 80 percent of the patients. These data demonstrate the safety and efficacy of selective observation of patients with penetrating neck trauma, and confirm that clinical signs are a reliable indicator of significant injury.
A review of 817 mitral and aortic Silastic ball valve implantations with a follow-up of 3,554 total patient-years yielded only seven cases of valve thrombosis. Time-related risk was 0.4% per patient-year in the mitral position and 0.1% per patient-year in the aortic position. Four of five mitral and one of two aortic ball valve thromboses were successfully managed by valve rereplacement . At least five of the seven patients presented with a prodrome (lasting at least 3 months) of symptoms of progressive heart failure and, occasionally, embolic episodes due to gradually increasing prosthetic stenosis by thrombus. This lengthy time course is in contrast to the more frequent rapid catastrophic thrombosis that occurs with the Björk-Shiley tilting disc valve. Recognition of the prodrome of Silastic ball valve thrombosis provides an opportunity for life-saving surgical intervention.
Eighteen years of continuous clinical use with the Starr-Edwards ball-valve prosthesis provides an extensive data base for comparison with more recently introduced cardiac prostheses, and establishes the credentials of this valve for current clinical use. Since 1965, 558 aortic (model 1260) and 285 mitral (model 6120) ball-valve prostheses have been inserted at the University of Oregon. Thromboembolic rates for the entire series (1965-1983) and our more recent experience (1973-1983) were 3.8% per year and 2.8% per year for the aortic valve; and 5.1% per year and 2.6% per year for the mitral valve. Patients who had experienced one embolic episode were substantially more likely to experience a subsequent event. Thrombotic stenosis was seen at rates of 0.1% per patient year and 0.4% per patient year for the aortic and mitral valves, respectively. These results are compared with other current series using a variety of mechanical and tissue prostheses. The Starr-Edwards valve remains a durable mechanical cardiac prosthesis with thromboembolic complications similar to most other current prostheses. Thrombotic stenosis tends to be rare, gradual, and electively managed as opposed to the sudden, unpredictable, and catastrophic thrombosis seen with tilting disc valves.